High Quality Images - not high quality on iPad/iPhone

This may not be a “bug” but a limitation of my devices.

I notice that the high quality coin scans I send/receive in private messages via my laptop are great, but when trying to view them on mobile devices (iPad/iPhone) they become very low quality. Does anyone else have this issue, and is there a way to improve the images? I am a relatively new apple user.

Only me I guess